WO2015093440A1

WO2015093440A1 - Pneumatic tire and method for producing same

Info

Publication number: WO2015093440A1
Application number: PCT/JP2014/083153
Authority: WO
Inventors: 秀典土肥; 昌弘平野
Original assignee: 横浜ゴム株式会社
Priority date: 2013-12-16
Filing date: 2014-12-15
Publication date: 2015-06-25
Also published as: US10857835B2; US20160318344A1; JP6455442B2; JPWO2015093440A1; DE112014005712T5; CN105793067A

Abstract

Provided are a pneumatic tire and a method for producing same, whereby high levels of road noise reduction performance and high-speed durability performance can be ensured without compromising uniformity. In a step for layering, over the outer periphery of a belt layer (5) constituting a green tire (G), belt-reinforcing layers (6) for respectively covering the left and right tire-widthwise ends of the belt layer (5), the belt-reinforcing layers (6) being set apart from the outer periphery in the tire width direction, strip materials (7) constituting the belt-reinforcing layers (6) are inclined in the same direction relative to the tire circumferential direction and the materials are wound at least once in a helical formation in the tire circumferential direction, whereby the respective belt-reinforcing layers (6) are formed.

Description

Pneumatic tire and manufacturing method thereof

The present invention relates to a pneumatic tire and a manufacturing method thereof, and more particularly to a pneumatic tire and a manufacturing method thereof that can ensure road noise reduction performance and high-speed durability performance at a high level without deteriorating uniformity.

A structure of a pneumatic tire is known in which a belt layer is disposed on the outer peripheral side of the carcass layer, and a belt reinforcing layer is disposed so as to cover both ends of the belt layer in the tire width direction (see, for example, Patent Document 1). . According to this tire structure, the movement in the tire radial direction at both ends of the belt layer in the tire width direction during travel is suppressed by the belt reinforcing layer, so that road noise can be reduced. Furthermore, the high-speed durability of the tire can also be improved. If this belt reinforcing layer is disposed so as to protrude outward in the tire width direction, it is possible to further expect to reduce road noise and improve high-speed durability of the tire.

As illustrated in FIG. 8, the belt reinforcing layer 6 is formed by winding a strip material 7 including one or more fiber cords in a spiral shape so that the fiber cords are substantially parallel to the tire circumferential direction. Has a winding structure. When the belt reinforcing layer 6 is separated in the tire width direction and is disposed so as to cover both ends of the belt layer 5 in the tire width direction, a strip is formed on the outer peripheral side of the belt layer 5 on the forming drum 10 as illustrated in FIG. The material 7 is wound and laminated. Although the belt layer 5 is laminated on the outer peripheral side of the carcass layer on the forming drum 10, the carcass layer is not shown in FIG.

In the step of laminating the belt reinforcing layer 6, each winding head is rotated while holding the strip material 7 by the winding head 11 and feeding it to the outer peripheral surface of the belt layer 5 while rotating the forming drum 10 in one circumferential direction. 11 is moved along the guide 12. At this time, the left winding head 11 is moved from the center in the drum width direction to the left in the drum width direction, and the right winding head 11 is moved from the center in the drum width direction to the right in the drum width direction. That is, the strip material 7 constituting each belt reinforcing layer 6 is set so that the end 7a in the longitudinal direction serving as the winding start point is set closer to the center in the tire width direction than the longitudinal end 7b serving as the winding end point. The drum is spirally wound around the drum in the circumferential direction, inclined in different directions. Therefore, the tire width direction intervals S1 and S2 between the belt reinforcing layers 6 spaced apart in the tire width direction change in the tire circumferential direction as illustrated in FIG. 8 (that is, S1 ≠ S2). This causes a problem that tire uniformity deteriorates.

Japanese Unexamined Patent Publication No. 2009-56938

An object of the present invention is to provide a pneumatic tire that can ensure road noise reduction performance and high-speed durability performance at a high level without deteriorating uniformity, and a method for manufacturing the same.

In order to achieve the above object, a pneumatic tire according to the present invention includes a belt layer embedded on the outer circumferential side of the carcass layer, and the belt layer on the outer circumferential side of the belt layer covering the left and right ends in the tire width direction of the belt layer. In a pneumatic tire provided with a belt reinforcing layer that is embedded in the tire width direction so as to be separated from each other, each belt reinforcing layer has a strip material constituting each reinforcing layer arranged in the same direction with respect to the tire circumferential direction. It is formed by inclining and winding at least one round in the tire circumferential direction in a spiral shape.

The method for manufacturing a pneumatic tire according to the present invention includes a belt reinforcing layer that covers each of a left end portion and a right end portion in the tire width direction of the belt layer in the tire width direction on the outer peripheral side of the annular belt layer forming the green tire. In the manufacturing method of a pneumatic tire in which a green tire having a structure in which the green tires are stacked apart from each other is formed and then the green tire is vulcanized, in the step of laminating the belt reinforcing layers, strips constituting the belt reinforcing layers The material is inclined in the same direction with respect to the tire circumferential direction and is wound spirally at least once in the tire circumferential direction.

According to the pneumatic tire of the present invention, the belt reinforcing layer embedded on the outer peripheral side of the belt layer so as to cover the left end portion and the right end portion in the tire width direction of the belt layer includes at least the strip material spirally in the tire circumferential direction. Since it is formed by winding one round, the strip material forms a strong annular belt reinforcing layer. Therefore, since the movement in the tire radial direction at both ends of the running belt layer in the tire width direction is sufficiently suppressed by the belt reinforcing layer, road noise can be reduced at a high level. In addition, the high-speed durability of the tire can be improved at a high level. In addition, since the strip materials constituting each belt reinforcing layer are inclined in the same direction relative to the tire circumferential direction and spirally wound in the tire circumferential direction, the tire width between the belt reinforcing layers spaced apart from each other The direction interval is substantially constant in the tire circumferential direction. Therefore, it is possible to avoid the problem that the uniformity of the tire is deteriorated due to the belt reinforcing layer.

According to the method for manufacturing a pneumatic tire of the present invention, the belt reinforcing layer covering the left end portion and the right end portion in the tire width direction of the belt layer is provided on the outer peripheral side of the annular belt layer constituting the green tire. In the step of laminating the belts separated in the width direction, the strip members constituting each belt reinforcing layer are inclined in the same direction with respect to the tire circumferential direction and wound at least one round in the tire circumferential direction in a spiral manner. In the tire, the strip material forms a strong annular belt reinforcing layer. Therefore, since the movement in the tire radial direction at both ends of the running belt layer in the tire width direction is sufficiently suppressed by the belt reinforcing layer, road noise can be reduced at a high level. In addition, the high-speed durability of the tire can be improved at a high level. In addition, since the strip materials constituting each belt reinforcing layer are inclined in the same direction relative to the tire circumferential direction and spirally wound in the tire circumferential direction, the tire width between the belt reinforcing layers spaced apart from each other The direction interval is substantially constant in the tire circumferential direction. Therefore, it is possible to avoid the problem that the uniformity of the tire is deteriorated due to the belt reinforcing layer.

FIG. 1 is a tire meridian cross-sectional view illustrating the internal structure of the pneumatic tire of the present invention. FIG. 2 is a plan view illustrating the belt reinforcing layer of FIG. FIG. 3 is an explanatory view schematically illustrating a step of laminating the belt reinforcing material of FIG. 2 on the outer peripheral side of the belt layer. FIG. 4 is a cross-sectional view illustrating a molded green tire. FIG. 5 is an explanatory view schematically illustrating a step of laminating the belt reinforcing layer on the left side in the tire width direction of FIG. 2 on the outer peripheral side of the belt layer. FIG. 6 is an explanatory view schematically illustrating a step of laminating the belt reinforcing layer on the right side in the tire width direction of FIG. 2 on the outer peripheral side of the belt layer. FIG. 7 is a tire meridian cross-sectional view illustrating the internal structure of another embodiment of the pneumatic tire of the present invention. FIG. 8 is a plan view illustrating a conventional belt reinforcing layer. FIG. 9 is an explanatory view schematically illustrating a step of laminating the belt reinforcing layer of FIG. 8 on the outer peripheral side of the belt layer.

Hereinafter, the pneumatic tire of the present invention and the manufacturing method thereof will be described based on the embodiments shown in the drawings.

The pneumatic tire 1 of the present invention illustrated in FIGS. 1 and 2 is a radial tire, and reinforcing cords extending in the tire radial direction are disposed at a predetermined interval in the tire circumferential direction between a pair of left and right bead portions 2. A carcass layer 4 embedded in the rubber layer is extended. In the figure, the C arrow direction indicates the tire circumferential direction, the W arrow direction indicates the tire width direction, and the alternate long and short dash line CL indicates the tire width direction center line. Both ends of the carcass layer 4 in the tire width direction are folded back from the inner side to the outer side in the tire width direction so as to sandwich the bead filler 2b around the annular bead core 2a constituting the bead part 2. The carcass layer 4 is disposed on the outer peripheral side of the inner liner 3 serving as the innermost peripheral layer. The inner liner 3 extends to the left and right bead portions 2.

A tread rubber having a predetermined pattern is disposed on the tread portion 9c, and the outer side of the carcass layer 4 of the shoulder portion 9b and the outer side of the carcass layer 4 of the side portion 9a are covered with rubber. Two belt layers 5 (5a, 5b) are embedded in the outer peripheral side of the carcass layer 4 of the tread portion 9c. These

belt layers

5a and 5b are arranged so that the reinforcing cords are inclined with respect to the tire circumferential direction and the reinforcing cords cross each other between the layers. The inner circumferential belt layer 5a has a larger tire width direction dimension (belt width) than the outer circumferential belt layer 5b.

A belt reinforcement layer 6 is embedded on the outer peripheral side of the belt layer 5b on the outer peripheral side so as to be spaced apart from each other in the tire width direction and cover the left end portion and the right end portion of the belt layer 5 in the tire width direction. The specifications of each belt reinforcing layer 6 are substantially the same. In this embodiment, each belt reinforcing layer 6 is embedded so as to protrude outward in the tire width direction from the end in the tire width direction on the side where the belt reinforcing layer 6 of the belt layer 5 is disposed. That is, the left belt reinforcing layer 6 protrudes to the left in the tire width direction from the left end in the tire width direction of the belt layer 5 (widest belt layer 5a), and the right belt reinforcing layer 6 extends to the belt layer 5 (widest belt layer 5a). The belt layer 5a) protrudes to the right in the tire width direction from the right end in the tire width direction.

Each belt reinforcing layer 6 is formed by winding the strip material 7 spirally at least once in the tire circumferential direction. The strip material 7 is formed by embedding a plurality of extended reinforcing cords 8 in a rubber layer, and the extending direction of the reinforcing cords 8 is the longitudinal direction of the strip material 7. In FIG. 2, the reinforcing cord 8 embedded in the strip material 7 by cutting out a part of the strip material 7 is illustrated. The strip members 7 constituting each belt reinforcing layer 6 are spirally wound around the tire circumferential direction while being inclined in the same direction with respect to the tire circumferential direction (that is, with respect to the tire width direction center line CL). Yes. The strip material 7 is spirally wound so that adjacent widthwise ends are in contact with each other substantially without gaps.

The width of the strip material 7 is, for example, 5 mm to 20 mm. As the reinforcing cord 8, nylon fiber cord, polyester fiber cord, polyketone fiber cord, lyocell fiber cord, polyamide fiber cord, or the like can be used.

In this pneumatic tire 1, each belt reinforcing layer 6 is formed by winding the strip material 7 in a spiral manner in at least one turn in the tire circumferential direction. As a result, the strip material 7 forms a strong annular belt reinforcement layer 6, and the movement in the tire radial direction of both ends of the running belt layer 5 in the tire width direction is sufficiently suppressed by the strong belt reinforcement layer 6. The Therefore, road noise can be reduced at a high level, and high-speed durability of the tire can also be improved at a high level. In this embodiment, each belt reinforcing layer 6 is embedded so as to protrude outward in the tire width direction from the end of the belt layer 5a in the tire width direction, so that the road noise reduction effect and the high-speed durability performance of the tire are further improved. To do.

Further, since the strip members 7 are inclined in the same direction with respect to the tire circumferential direction and spirally wound in the tire circumferential direction, the tire width direction spacing S1 between the belt reinforcing layers 6 that are separated from each other, S2 is substantially constant in the tire circumferential direction (S1≈S2). Thereby, since the uniformity of the pneumatic tire 1 improves, the deterioration of the uniformity resulting from the belt reinforcement layer 6 can be avoided.

In this embodiment, the respective longitudinal ends 7a of the strip members 7 constituting the respective belt reinforcing layers 6 located on the tire width direction central portion side are set at substantially the same position in the tire circumferential direction. In addition, the respective longitudinal ends 7b located on the outer side in the tire width direction with respect to the longitudinal ends 7a are set at substantially the same position in the tire circumferential direction. With this configuration, the uniformity of the pneumatic tire 1 is further improved. It is more preferable that the positions in the tire circumferential direction of the respective ends 7a, 7b in the longitudinal direction of the strip material 7 are substantially the same.

Next, a method for manufacturing the pneumatic tire 1 will be described.

3A and 3B are wound and disposed on the forming drum 10 illustrated in FIG. 3 as a laminated body including an inner liner 3 and a carcass layer 4 formed in an annular shape. In FIG. 3, these members are not shown in order to make the drawing easier to see. The green tire G is formed in a state in which the annular belt layer 5 (5a, 5b), the belt reinforcing layer 6, tread rubber, and the like are laminated on the outer peripheral side of the laminated body. Alternatively, the belt layer 5 (5a, 5b) is wound around the outer peripheral surface of the forming drum 10 to form an annular shape, and then the belt reinforcing layer 6 is laminated on the outer peripheral side of the belt layer 5, and then each belt reinforcing layer is laminated. The other laminated body can also be formed by laminating other tire constituent members such as tread rubber constituting the tread portion 9c on the outer peripheral side of 6. In this case, separately from the other laminate, one laminate composed of the annular inner liner 3 and the carcass layer 4 is formed, and the other laminate is laminated on the outer peripheral side of the one laminate. Then, the green tire G is formed. That is, in the method for manufacturing a pneumatic tire according to the present invention, the green tire G can be formed by various procedures, but has the characteristics described later when the belt reinforcing layer 6 is laminated.

In the step of laminating each belt reinforcing layer 6, the strip material 7 constituting each belt reinforcing layer 6 is inclined in the same direction with respect to the tire circumferential direction and wound spirally in the drum circumferential direction at least once. At this time, as illustrated in FIG. 3, the belt reinforcing layer that covers the left end portion in the tire width direction of the belt layer 5 while rotating the annular belt layer 5 constituting the green tire G being molded in one circumferential direction. 6, the longitudinal end 7 a serving as the winding start point of the strip material 7 is set at the center in the tire width direction, and the longitudinal end 7 b serving as the winding end point is set to the tire width from the winding start point. It is set at the outer side in the direction and wound at least once in the tire circumferential direction in a spiral manner. Specifically, while rotating the forming drum 10 in one circumferential direction, the strip material 7 is held by the winding head 11 and fed to the outer peripheral surface of the belt layer 5, and the winding head 11 is moved along the guide 12 along the tire width. The strip material 7 is wound spirally by moving from the center in the direction to the left in the tire width direction.

The other strip material 7 constituting the belt reinforcing layer 6 covering the right end of the belt layer 5 in the tire width direction is wound around the annular belt layer 5 constituting the green tire G being molded and the left strip material 7 is wound. The longitudinal end 7b as the winding start point is set on the outer side in the tire width direction while rotating in the same direction as the circumferential direction in the case of the tire, and the longitudinal end 7a as the winding end point is set to the tire from the winding start point. It is set at the center in the width direction and wound at least once in the tire circumferential direction in a spiral shape. Specifically, while rotating the forming drum 10 in one circumferential direction, the strip material 7 is held by the winding head 11 and fed to the outer peripheral surface of the belt layer 5, and the winding head 11 is moved along the guide 12 along the tire width. The strip material 7 is wound spirally by moving from the right side in the direction to the center in the tire width direction. According to this laminating process, there is an advantage that the right and left strip members 7 can be wound simultaneously.

In this embodiment, the respective belt reinforcing layers 6 are laminated so as to protrude outward in the tire width direction from the end in the tire width direction on the side where the belt reinforcing layers 6 of the widest belt layer 5a are laminated. Further, the longitudinal ends 7a of the strip members 7 constituting the respective belt reinforcing layers 6 that are located on the center side in the tire width direction are set at the same position in the tire circumferential direction, and the tire width direction of these strip members The longitudinal ends 7b located outside are set at the same position in the drum circumferential direction.

After laminating the belt reinforcing layers 6 in this manner, another tire constituent member such as a tread rubber constituting the tread portion 9c is laminated on the outer peripheral side of each belt reinforcing layer 6 and green as illustrated in FIG. The tire G is molded. Next, by vulcanizing the green tire G, the pneumatic tire 1 illustrated in FIG. 1 is manufactured.

Each belt reinforcing layer 6 can be laminated by another method illustrated in FIGS. The belt layer 5 is wound around the outer peripheral surface of the forming drum 10 illustrated in FIGS.

In this method, as illustrated in FIG. 5, a belt reinforcing layer that covers the left end of the belt layer 5 in the tire width direction while rotating the annular belt layer 5 constituting the green tire G being molded in one circumferential direction. 6, the longitudinal end 7 a serving as the winding start point of the strip material 7 is set closer to the center in the tire width direction than the left end of the belt layer 5, and the longitudinal end 7 b serving as the winding end point is defined. It is set on the outer side in the tire width direction from the winding start point, and is wound at least one round in the tire circumferential direction in a spiral shape. Specifically, while rotating the forming drum 10 in one circumferential direction, the strip material 7 is held by the winding head 11 and fed to the outer peripheral surface of the belt layer 5, and the winding head 11 is moved along the guide 12 along the tire width. The strip material 7 is wound spirally by moving from the center in the direction to the left in the tire width direction.

Further, the other strip material 7 constituting the belt reinforcing layer 6 covering the right end portion of the belt layer 5 in the tire width direction is an annular belt layer 5 constituting the green tire G being molded as illustrated in FIG. While rotating in a direction opposite to one circumferential direction, the longitudinal end 7a serving as the winding start point is set closer to the center in the tire width direction than the right end of the belt layer 5, and the longitudinal end 7b serving as the winding end point is set. Is set on the outer side in the tire width direction from the winding start point and wound at least one round in the tire circumferential direction in a spiral shape. Specifically, the outer peripheral surface of the belt layer 5 is held by the winding head 11 while the molding drum 10 is rotated in a direction opposite to the one circumferential direction when the left strip member 7 is wound. The strip 11 is spirally wound by moving the winding head 11 along the guide 12 from the center in the tire width direction to the right in the tire width direction.

In this embodiment, the respective belt reinforcing layers 6 are laminated so as to protrude outward in the tire width direction from the end in the tire width direction on the side where the belt reinforcing layers 6 of the widest belt layer 5a are laminated. Further, the longitudinal ends 7a of the strip members 7 constituting the respective belt reinforcing layers 6 that are located on the center side in the tire width direction are set at the same position in the tire circumferential direction, and the tire width direction of these strip members The ends 7b in the longitudinal direction located outside are set at the same position in the tire circumferential direction.

In this method, since the end 7a in the longitudinal direction, which is the winding start point of each strip material 7, becomes the outer peripheral surface of the belt layer 5, the winding start point can be firmly fixed to the belt layer 5. Therefore, the strip material 7 can be stably wound in a spiral shape. When the belt reinforcing layer 6 is laminated on the outer side in the tire width direction with respect to the end of the widest belt layer 5a in the tire width direction, if the winding start point of the strip material 7 is set at a position away from the belt layer 5a, the strip material 7 is Although it is difficult to stably wrap, the strip material 7 can be wound very stably in the method illustrated in FIGS. Therefore, it is more advantageous to ensure road noise reduction performance and high-speed durability performance at a high level without deteriorating the uniformity of the pneumatic tire 1.

In the embodiment described above, the number of the belt reinforcing layers 6 embedded in the outer peripheral side of the belt layer 5 is one layer, but a plurality of belt reinforcing layers 6 may be embedded in the vertical direction. From the viewpoint of weight reduction of the tire, it is preferable that the number of the belt reinforcing layers 6 embedded in the left end portion and the right end portion of the belt layer 5 in the tire width direction is one.

In the pneumatic tire 1 of the present invention, as illustrated in FIG. 7, each belt reinforcing layer 6 is a tire from the end in the tire width direction on the side where each belt reinforcing layer 6 of the widest belt layer 5 a is embedded. A configuration that does not protrude outward in the width direction can also be adopted.

Using two types of test tires (Examples, conventional examples), which are pneumatic tires of the same specification for passenger cars, with different specifications for the embedding of the belt reinforcement layer, RFV (Radial Force Variation), RRO (Radial Run Out) ) And the results are shown in Table 1. In Table 1, the measured value of the example is shown as an index with the measured value of the conventional example as 100 as a reference. The smaller the index value, the better the tire uniformity.

In the belt reinforcing layer of the example, as illustrated in FIG. 2, the distances S1 and S2 in the tire width direction of the belt reinforcing layers are substantially the same in the tire circumferential direction. The longitudinal ends of the left and right strip members located on the center side in the tire width direction are set at substantially the same position in the tire circumferential direction. In the belt reinforcing layer of the conventional example, as illustrated in FIG. 8, the tire width direction intervals S <b> 1 and S <b> 2 of the belt reinforcing layers of each other changed in the tire circumferential direction. The longitudinal ends of the left and right strip members located on the center side in the tire width direction are set at substantially the same position in the tire circumferential direction.

From the results in Table 1, it can be seen that the examples are improved in RFV and RRO and superior in uniformity as compared with the comparative example.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Bead part

2a Bead core

2b Bead filler 3 Inner liner 4 Carcass layer 5 Belt layer 6 Belt reinforcement layer 7 Strip material 7a End in the longitudinal direction (end located on the inner side in the tire width direction)
7b End in the longitudinal direction (end located on the outer side in the tire width direction)
8 Reinforcing cord

9a Side portion

9b Shoulder portion 9c Tread member 10 Molding drum 11 Winding head 12 Guide G Green tire

Claims

A belt layer embedded on the outer peripheral side of the carcass layer, and a belt reinforcing layer embedded on the outer peripheral side of the belt layer so as to cover the left end portion and the right end portion in the tire width direction of the belt layer and are spaced apart from each other in the tire width direction. In each of the pneumatic tires including the above, each belt reinforcing layer is spirally wound at least one round in the tire circumferential direction by inclining the strip members constituting the respective reinforcing layers in the same direction with respect to the tire circumferential direction. A pneumatic tire characterized by being formed.
The pneumatic tire according to claim 1, wherein each belt reinforcing layer is embedded so as to protrude outward in the tire width direction from an end in the tire width direction on the side where each belt reinforcing layer of the belt layer is embedded.
The longitudinal ends of the strip materials constituting the respective belt reinforcing layers located on the center side in the tire width direction are set at the same position in the tire circumferential direction, and are located outside the strip width direction of the strip materials. The pneumatic tire according to claim 1 or 2, wherein the other ends in the longitudinal direction are set at the same position in the tire circumferential direction.
The pneumatic tire according to any one of claims 1 to 3, wherein each belt reinforcing layer is embedded in one layer.
Forming a green tire with a structure in which a belt reinforcement layer covering the left and right ends of the belt layer in the tire width direction is laminated on the outer periphery of the belt layer formed in an annular shape that constitutes the green tire and spaced apart in the tire width direction. Then, in the pneumatic tire manufacturing method for vulcanizing the green tire, in the step of laminating each belt reinforcing layer, the strip materials constituting each belt reinforcing layer are in the same direction with respect to the tire circumferential direction. A method of manufacturing a pneumatic tire, wherein the pneumatic tire is wound at least once in the circumferential direction in a spiral manner.
6. The method for manufacturing a pneumatic tire according to claim 5, wherein each belt reinforcing layer is stacked so as to protrude outward in the tire width direction from an end in the tire width direction on the side where the belt reinforcing layers of the belt layer are stacked.
The longitudinal ends of the strip members constituting the respective belt reinforcing layers, which are positioned at the center in the tire width direction, are set at the same position in the tire circumferential direction, and the strip members are positioned at the outer sides in the tire width direction. The method for manufacturing a pneumatic tire according to claim 5 or 6, wherein the other ends in the direction are set at the same position in the tire circumferential direction.
While rotating the belt layer formed in the annular shape in one circumferential direction, the winding start point of one strip material is set closer to the center in the tire width direction than the winding end point, and the strip material is spirally formed in the tire circumferential direction. The belt layer formed in an annular shape is rotated in a direction opposite to the one circumferential direction, and the winding start point of the other strip material is set closer to the center in the tire width direction than the winding end point. The method for manufacturing a pneumatic tire according to any one of claims 5 to 7, wherein the strip material is spirally wound at least once in the tire circumferential direction.
While rotating the belt layer formed in the annular shape in one circumferential direction, the winding start point of one strip material is set closer to the center in the tire width direction than the winding end point, and the strip material is spirally formed in the tire circumferential direction. This strip is formed by winding the annular belt layer in the same direction as the circumferential direction, and setting the winding start point of the other strip material to the outside in the tire width direction from the winding end point. The method for manufacturing a pneumatic tire according to any one of claims 5 to 7, wherein the material is spirally wound at least once in the tire circumferential direction.